Conventional unmanned aerial vehicles are typically either configured as fixed wing airplanes or rotary wing helicopters. Fixed wing airplanes excel at flight endurance, range, and speed but are limited by the large amount of space that is required for takeoff and landing and must always continue forward, often at significant speeds, thus limiting their ability to maneuver through tight spaces. Conversely, rotary wing helicopters excel at minimizing required takeoff and landing space and can stop in a midair hover and are thus more maneuverable than fixed wing airplanes but have limited flight endurance and range.
In recent years, a new class of unmanned aerial vehicles broadly known as multicopters or vertical take-off and landing (VTOL) aircraft have emerged which mimic a helicopter's hover and vertical takeoff and landing capabilities with less mechanical complexity and are often quite agile in flight.
Many inexpensive UAVs are fragile and/or difficult to control. UAVs which are more rugged and/or easier to control are typically expensive. Flight controllers are available from different sources including hovering flight controllers and forward flight controllers. These flight controllers generally make it easier to control an UAV. But, the transition between the hover and the forward flight modes can be difficult. See U.S. Pat. Nos. 3,193,218, 6,882,889, 7,946,582, Published U.S. Patent Application 2014/0339354, Canadian Patent No. 2571372 and Hardware-in-the-Loop Testing of the V-22 Flight Control System Using Piloted Simulation by C. Robinson et al. Presented at the AIAA Flight Simulation Technologies Conference, Boston, Mass. Aug. 14-16, 1989 all incorporated herein by this reference.